敲除kdm4ab对斑马鱼低温耐受能力的影响

Knockout of zebrafish kdm4ab affects cold tolerance

为深入研究kdm4ab基因在鱼类低温胁迫下的作用,以斑马鱼(Danio rerio)为模式生物,利用CRISPR/Cas9基因编辑技术构建kdm4ab^(-/-)斑马鱼品系。RT-qPCR结果显示,与WT斑马鱼相比,kdm4ab^(-/-)斑马鱼的kdm4ab mRNA表达量显著下调(P<0.000 1),而kdm4c的mRNA表达量补偿性增加(P<0.05)。斑马鱼行为轨迹跟踪系统检测发现,18℃低温下kdm4ab^(-/-)斑马鱼幼鱼的最大加速度显著降低(P<0.05)。8℃低温下kdm4ab^(-/-)斑马鱼的半数致死时间(LT50)显著低于WT斑马鱼(P<0.000 1);低温处理后kdm4ab^(-/-)斑马鱼的γH2A.X表达量明显增加,ROS水平升高,即DNA损伤增强。研究表明,敲除kdm4ab基因降低了低温下斑马鱼的耐受能力及运动能力,这为鱼类的低温耐受机制研究提供新思路。

To explore the role of kdm4ab in fish under low temperature,kdm4ab^(-/-)zebrafish was constructed by CRISPR/Cas9.RT-qPCR showed that the mRNA expression level of kdm4ab in kdm4ab^(-/-)zebrafish was significantly reduced(P<0.0001),while the expression of kdm4c level was compensatively increased(P<0.05).The detection of zebrafish behavior trajectory tracking system showed that the maximum acceleration of kdm4ab^(-/-)larval zebrafish was significantly decreased at 18℃(P<0.05),compared with that of WT larval zebrafish.At 8℃,the LT 50 of kdm4ab^(-/-)zebrafish was significantly lower than that of WT zebrafish(P<0.0001).After low temperature treatment,the expression ofγH2A.X in kdm4ab^(-/-)zebrafish increased significantly,and the level of ROS increased,which indicated that the DNA damage was enhanced.The results showed that kdm4ab had a certain effect on the cold tolerance of zebrafish,which also provided a new idea for the low temperature tolerance mechanism of fish.